Sheet unit



SHEET UNIT Filed March 4. 1931 fndenior;

En, SanZsJ;

Patented Jan. 12, 1932 UNITED STATES a 8, JR, WEST CHESTER,PENNSYLVANIA.

SHEET UNIT Application filed March 4, 1981. Serial No. 519,969.

My invention relates to improvements in sheet units es ecially adaptedfor books of the loose leaf binder type. The object is to provideimproved means for preserving old letters, manuscripts, or old documentsso that the same may be maintained fiat and protected from theatmosphere and from contact with the hand or other contacts that mighttend to deface the same, and at the same time to permit inspection ofthe same, as to one side or both sides as may be required.

To this end a multi ply sheet unit is provided comprising sheet elementsarranged and associated to receive between the several 5 plies a letteror other exhibit document pro tected as above described and at the sametime exposed to view as to one or both sides.

Referring to the drawings which illustrate merel by wa of examplesuitable means for e ecting t e invention p v Fig. 1 is a plan viewshowin the multiply sheet elements before assem ling into a sheet unit.

Fig. 2 is a plan view of the sheet'unit assembled and with an exhibitdocument in place therein.

Fig. 3 is a fragmentary section on line 3, 3 of Fig. 2, greatlyenlarged.

. Fig. 4 is a view in perspective of a book containing a number of saidsheet units.

Similar numerals refer to similar parts throughout the several views. aI

In accordance with the example shown in the drawings, the'outer sheetelements 7 and 8 are preferably made of heavy paper or other fibrous ortextile material. Element 7 is shown as provided with a window opening'9 having a very substantial margin or frame 10 surrounding saidopening. A line of suitable adhesive is provided upon the inner face ofthe sheet, close to the margin of the window opening, as indicated at11. This sheet element 7 is also shown as provided with holes 13 forreceiving the rings 14, or posts or other fastening devices, commonlyused in connection with loose leaf binders.

The sheet element 8 is shown as provided with the window opening 15,adapted to register with opening 9 of sheet element 7 and a similar lineof adhesive 11. Another line of adhesive is provided upon the same facenear the outer margin of the sheet, as at 12. In other words elements 7and 8 are practically similar, except that one of these elements neednot have the line of adhesive 12.

The sheet 17 is of transparent material such as heavy grade cellophane.Its dimensions are slightly greater than the window an opening 9 ofelement 7, so as to extend over the line of adhesive 11, whereby saidsheet 17 is firmly secured to the inner face of element 7. The sheet 18is similar to sheet 17 and is secured in the same way to sheet elee5ment 8. The exhibit document 19 may be approximately of the samedimensions as that of the window, or it may be ofless dimensions ifdesired. Documents or exhibit sheets are placed in desired relationshiwith the windows of elements 7 and 8 an these then brought together withthe said documents or other exhibits betweenthem and the transparentsheets, and the said sheet elements ,7 and 8 then have their adjacentfaces near their outer margins firmly secured together by the line ofadhesive 12, either continuously around said margins, or at separatedpoints around said margins. This arrangement ensures a clamping pressureof so the sheet elements 7 and 8 and their respective transparent sheetsupon said exhibit. Where it is desired to expose to view both sides ofan exhibit sheet, the o posite window openings of the cooperating s eetelements 7 and 8 are made to register, and to correspond approximatelywith the dimensions of the respective exhibit areas to be exposed toview.

Where only one side of a sheet exhibit is to be visible then two suchexhibits may be inserted between sheet elements 7 and 8 and theirtransparent sheets, with the window of dimensions corresponding to theareas of the respective exhibit sheets, or if and where preferred, whenonly one side of an exhibit sheet is to be exposed to view, one sheetelement may be used, such as 7, provided with the window opening ofrequired dimensions and the transparent sheet secured thereto around thewindow margin, while the other sheet element may be without any openingwhatsoever.

This latter form may be preferred where very fragile exhibits are to bepreserved, and only one side is to be visible, as the solid backing ofthe unbroken sheet element forms a greater protection for said exhibit.

It will of course be understood that the sheet elements may be made in anumber of ways, for example a single window opening such as 15 may bedivided into two or more smaller Window openings by securing stripsacross said first opening and separate transparent sheets may beprovided for each opening where desired.

In cases where it is desired to preserve small portraits or otherexhibits in medallion form, a number of small openings may be b providedin a single sheet element. If desired the outer sheet elements may besecured together only partly around their outer margins so as to leaveunsecured spaces for the insertion of exhibits, where the same are ofsuch character as to permit such insertion, but where the exhibits arevery old or fragile it is desirable to lay the same upon the transparentsheet covering the window opening with which it is to be associated andthen to place the opposite sheet element upon it. In this way. theexhibit is clamped in frictional or pressure engagement between the twotransparent sheets or between a transparent sheet and the opposite sheetelement as the case may be.

The transparent sheet is preferably of heavy grade cellophane in orderto insure evenly distributed clamping action over the entire exhibitarea.

Documents or other sheet exhibits may in this way be preservedindefinitely and may be inspected from time to time without theslightest injury thereto.

Old letters which have become broken or nearly broken at their creases,may be smoothed out and under the gentle but constant pressure of thetransparent sheets may be so maintained without further deteriorationfor frequent inspection. Also the ink or pigment associated with theexhibit, by cause of the close contact of the transparent but waterproofsheet material such as cellophane, is effectively protected.

What I claim is 1. A multi-ply sheet unit, comprising-two sheetelements, one having a window opening and adhesive provided on the facethereof which is adjacent the other sheet element and approximate saidopening, a sheet of heavy grade cellophane, of dimensions slightlygreater than said window opening and extending over said adhesivewhereby said transparent sheet is secured to said sheet element, andmeans for securing together portions of the adjacent faces of said sheetelements so that said transparent sheet shall clamp with pressureengagement an exhibit sheet positioned between said sheet elements.

2. A multi-ply sheet unit, suitable for loose leaf binders or the like,comprising two sheet elements having window openings with adhesiveprovided on the adjacent faces of said sheet elements approximate themargins of said openings, sheets of cellophane, of dimensions slightlygreater than said respective window openings and extending over saidadhesive whereby a transparent sheet is secured to each sheet elementand over each window opening, and means for securing together portionsof the adjacent faces of said sheet elements, so that said transparentsheets shall clamp with pressure engagement the opposite sides of anexhibit sheet positioned etween said sheet elements.

3. A multi-ply sheet unit, suitable for loose leaf binders or the like,comprising two sheet elements having registering window openings withadhesive provided on the adjacent faces of said sheet elementsapproximate the margins of said openings, sheets of cellophane, ofdimensions slightly greater than said respective window openings andextend-' ing over said adhesive whereby a transparent sheet is securedto each sheet element and over each window opening, and means forsecuring together portions of the adjacent faces of said sheet elements,so that said transparent sheets shall clamp with pressure engagement theopposite sides of an exhibit sheet positioned between said sheetelements.

4:. A multi-ply sheet unit, suitable for loose leaf binders or the like,comprising two sheet elements, one having a window opening and adhesiveprovided on the face thereof which is adjacent the other sheet elementand approximate said opening, a sheet of cellophane, of dimensionsslightly greater than said window opening and extending over saidadhesive whereby said transparent sheet is secured to said sheeteleinent, and means for securing together portions of the adjacent facesof said sheet elements so that said transparent sheet shall clamp withpressure engagement an exhibit sheet positioned between said sheetelements and means for disengage-- ably securing a number of sheet unitsin book formation.

5. A multi-ply sheet unit, comprising two sheet elements, one at leasthaving a window opening with adhesive on the face of one sheet elementwhich is adjacent the other sheet element and approximate the margins ofsaid Window opening, a sheet of moistureproof transparent material ofsubstantial body and of dimensions slightly greater than said Windowopening and extending over said adhesive whereby said transparent sheetis secured to said sheet element, and means for securing togetherportions of the adjacent faces of said sheet elements so that saidtransparent sheet shall clamp with pressure engagement an exhibit sheetpositioned between said sheet elements.

HENRY PLEASANTS, JR.

